> On Stack Overflow, migration requires a super-majority when closing, which means that it will only be migrated automatically if four users vote to migrate it to the same site, on other sites, three votes for the same target suffice.
What is migration?
Migration allows an off-topic question to be gracefully moved to another site in the Stack Exchange network. It preserves the current revision of the question, all its answers, any comments on any post, as well as most of the votes.
Side effects of migration
Down votes are ...
@AndriyM Of course you're right: we should not throw rubbish to any other site, in the same way we don't want rubbish from them.
@PaulWhite Thanks! I knew there had to be some fine points about migration I wasn't aware of, but that FAQ article has proved to me there are some that are important to always keep in mind.
Really, unless the question is high quality and clearly on-topic, it's usually better just to vote to close (not migrate). The asker can normally delete here and re-ask on the target site anyway. Flag it if you see this sort of thing again.
About temporal tables in SQL Server 2016: no real surprises. They present as two tables (current value and history values) twinned through meta data, with enough syntactic sugar and sensible defaults to make it easy. There are a few obvious restrictions on what can be done, and a few less obvious ones that feel like v1 software. A nice addition to the portfolio but nothing revolutionary.
In the execution plan the "current" and "history" tables show up separately. There's a Concatenation operator if the predicates would touch both.
@PaulWhite The version I wrote initially just before casting my close vote. It didn't make sense once I realised the question was migrated, so I edited it.
Had to adjust it a bit, but basically this is what it was like initially:
Your question is unclear. It is also likely to be off-topic here while it may be on-topic on Stack Overflow. The community did attempt to migrate your question over there but it was closed as unclear and so the migration was rejected. If you are positive that yours is a database issue, please provide more details to make that point clear and allow your question to be re-opened. Otherwise, if I were you, I'd start afresh by posting the question on Stack Overflow (and deleting this one here) and see how it goes. You can always flag your question for moderator attention and request migration, if necessary. — Andriy M2 mins ago
And TIL: rejected migrations don't seem to be too much of a mess any more. Previously, when rejected on the target site, they used to remain locked on the originating site. Looks like that has been fixed.
MVCC somehow says that they can proceed without locking. They say that Version control systems do the same. I wonder how do they accomplish check-in without locking. Moreover, I revision control seems to relay upon the locking. Is it different from version control?
I do not get why 3-phase commit is more reliable. They say that 2-phase commit cannot stand the coordinator failure. But how the 3rd phase of the commit protocol can solve this problem?
Sorry, I believed that it is a standard treatment of 3PC.
Reading more carefully, 2-phase cannot recover if both cohort member and coordinator fail. You do not know if cohort member has received the commit message or not. But, I do not see how pre-commit helps here.
@ValentinTihomirov There is also a possibility that what you are talking about may not be trivial or common knowledge enough for people here to be able to quickly understand the issue, much less to have something to say in response.
@PaulWhite the help about says copyright 1990-1998
it's about 20 years old and AX's predecessor
the customer has a license issue, apparently the thing is licensed to have a database of a certain size, but you cannot get new licenses anymore (for obvious reasons)
@ValentinTihomirov Only I'm a little at a loss if this MVCC thing is indeed something not uncommon for database people to know about in some detail or if you are just taking your chances asking these questions here. (Don't get me wrong, please, I don't mind at all, just a little concerned for you, because your questions on this subject seem to have been getting little useful response.)
I designed standard reports using SSRS, and showed them to clients using report viewer in asp.net, but now requirements are to add adhoc reporting
but, I can't use SSRS report builder
because of 2 reasons,
1 - we want a nice looking interface 2 - our web app is multi tenant app (so security will a massive issue and emerging report builder with our app is aweful as welll)
Is there any point at which you become so familiar with your language/database/system that there is no need to test a new feature/configuration/query/etc. by contained/simulated testing before implementing it in your system (especially concerning a feature that modifies data)? Or is it always ess...
@MaxVernon Well there's a couple of points: it narrowly failed vote to reopen twice, has seven up votes and no downvotes, an OP that is still active on the site, and at least one comment that suggests someone would have answered had it not been closed.
Getting a reopen vote on dba is quite an achievement. Especially from users whose opinion I trust.
@PaulWhite hmmm in that case, I'd have no problem reopening it. It's not a particularly bad question. I expect the VtC was around "don't be stupid", without a lot of actual thought.
@PaulWhite I thought that was why you asked me about it above. I have no recollection of actually voting to reopen it, or what my particular thought was about why.
I suspect my reason was to allow Kenneth to answer.
I liked your answer here - catching the mismatched types is pretty darn important. I should have tweaked on that when I saw the datetime2 type; at least enough to check that. ;-)
@MaxVernon It's a topic close to my heart :) It's the a shame that OP asks so many questions and doesn't always come back to older ones. I'm still hopeful he will say something new on that page.
I deleted the "old" dll I found. It doesn't matter what ddl it is it's a custom dll for SSIS script task. There is a standard way of using a DLL for a script task. Which is why I am asking if there is another place where the dll can be. Since there seems to be a standard way of loading custom dlls in script task SSIS — Ya Wang14 mins ago
I am able to create standard reports using SSRS which work perfectly, but now I need to create ADHOC reporting engine/solution, we can't use standard SSRS report builder because of following reasons,
It looks awful and is very difficult to integrate it with our web application
Our web app is mu...
@Mathematics the questions says C# and asp.net, but you list "very difficult to integrate it with our web application" as one of the reasons to not use SSRS. Correct me if I'm wrong, but isn't it very simple to integrate them in that environment?, it's one of the "pro"s of it
I'm happy I found a bug that has cost me like 3 days to identify. And another 5 days to the developer that wrote (the code with the bug). So, drunk with relief.
In your question you say "one LUN assigned to a SQL Server VM" - what you want is one LUN assigned to the host VMware machine that can have multiple VMDKs for the SQL Server stored on it. This allows the VM to use a much larger number of threads to access the disk.
In order to get the best queu...
One of my vertica cluster node down, and in log file a found :
2016-03-19 20:01:55.263 Init Session:0x7f3420013970-b00000000a70ab [EE] <INFO> SortManager found maxMerges 7 too small(38 MB Assigned).
2016-03-19 20:01:55.263 Init Session:0x7f3420013970-b00000000a70ab [EE] <INFO> After disabling op...
What is the difference between these two apis?
Which one faster, reliable using Python DB API?
Upd:
I see two psql drivers for Django. The first one is psycopg2.
What is the second one? pygresql?
@PaulWhite Yeah I think it is a caching thing. I replaced it last week and updated my profile blurb too. I clicked the button to propagate the changes. I'd think that the cache would be invalidated by now though...
@TomV yeah when I was in the Marine Corps I looked sharp everyday. As you can see that didn't stick for the long term... I signed up for LinkedIn too. So far the longest I've ever stayed on social media is 6 months. We'll see if that holds true on LinkedIn too.
No I think it is nice to connect names with faces. You are legit people now instead of bots that Paul White created to get a more votes in a single day :)
@PaulWhite I haven't seen it yet but I'm sure its possible... :)
I have a T-SQL Boolean expression exp which can evaluate to TRUE, FALSE or (due to SQL's ternary logic) NULL.¹
Is there a generic method to null-coalesce such an expression to FALSE?
(Obviously, COALESCE(...some Boolean expression..., FALSE) won't work, since T-SQL does not have a FALSE literal...
@MaxVernon: I have taken your advise to "write a good question" and have greatly rewritten the question (made it less theoretical and more practical). I'd be glad for feedback. Is it easier to understand now? — Heinzi1 min ago
@swasheck Yeah I guess that's what I need to do. Figure out 1) how normal the data is and 2) for data that isn't normal, what distribution it resembles.
@JamesLupolt seems like you'd need to also calculate a seasonality (reading through the deck ... EMA is where i'm at and it seems like a good start). i used to know how to calculate that.
@swasheck Dejan's chapter in TSQL Querying talks about how to do EMA in TSQL. And there is this paper about how to update it incrementally if you can't keep all the measurements.
I'm only comparing each 15 minute segment on a given day of the week (e.g. for each metric, comparing every instance of 23:45:00-23:59:59 on a Sunday).
@swasheck Yeah, that's what I was thinking. I think it will help in situations where metric x is being blamed for new problem y, but the values of metric x haven't really changed much.
To give one example where a RIGHT JOIN may be useful.
Suppose that there are three tables for People, Pets, and Pet Accessories. People may optionally have pets and these pets may optionally have accessories
CREATE TABLE Persons
(
PersonName VARCHAR(10) PRIMARY KEY
);
INSERT INTO Pers...
@JamesLupolt the first step in any good statistical analysis is discovery ... i'd recommend a plot (using R, python, Excel, whatever) to look the trend of the particular metric you're analyzing
I want to start by saying everything I do is SQL Server so those are the examples I give. In general however this applies to any form of code regardless of system.
Let's start by breaking this down a bit.
Upgrades
You have a system and are about to upgrade some or all of it. For example upgr...
@A_V I received an email last friday cc @JamesLupolt
> Thank you for signing up to receive more information about our plans for running SQL Server on Linux. We look forward to sharing updates with you periodically. We are currently in the process of reviewing applicants and will begin sending out invitations to join the preview over the next few weeks, gradually increasing the number of participants added each week.
Is it right that with atomicity and isolation I reach the consistency? I mean that if I isolate transactions and perform their action atomically then I always have system in a consistent state, assuming that transactions do not violate the constraints.
What is migration?
Migration allows an off-topic question to be gracefully moved to another site in the Stack Exchange network. It preserves the current revision of the question, all its answers, any comments on any post, as well as most of the votes.
Side effects of migration
Down votes are ...
I am able to create standard reports using SSRS which work perfectly, but now I need to create ADHOC reporting engine/solution, we can't use standard SSRS report builder because of following reasons,
It looks awful and is very difficult to integrate it with our web application
Our web app is mu...
In your question you say "one LUN assigned to a SQL Server VM" - what you want is one LUN assigned to the host VMware machine that can have multiple VMDKs for the SQL Server stored on it. This allows the VM to use a much larger number of threads to access the disk.
In order to get the best queu...
What is the difference between these two apis?
Which one faster, reliable using Python DB API?
Upd:
I see two psql drivers for Django. The first one is psycopg2.
What is the second one? pygresql?
I have a T-SQL Boolean expression exp which can evaluate to TRUE, FALSE or (due to SQL's ternary logic) NULL.¹
Is there a generic method to null-coalesce such an expression to FALSE?
(Obviously, COALESCE(...some Boolean expression..., FALSE) won't work, since T-SQL does not have a FALSE literal...
To give one example where a RIGHT JOIN may be useful.
Suppose that there are three tables for People, Pets, and Pet Accessories. People may optionally have pets and these pets may optionally have accessories
CREATE TABLE Persons
(
PersonName VARCHAR(10) PRIMARY KEY
);
INSERT INTO Pers...
I want to start by saying everything I do is SQL Server so those are the examples I give. In general however this applies to any form of code regardless of system.
Let's start by breaking this down a bit.
Upgrades
You have a system and are about to upgrade some or all of it. For example upgr...
